The Dutch and British just took home the natives of their colonies as immigrants who opened restaurants. Why try to emulate when you can get the real deal?
If I hear that an Indian restaurant locally has been busted by immigration, I immediately head round.
Also, the reason most British food is bland is because of rationing during WW2. People who grew up back then ate food which was made with limited resources and that was the food they felt nostalgic for and made for their children, who then went on to make it for their own children.
France is (mostly) not an island and they weren't besieged during WWII.
I've also heard that Britain rolling early with the Industrial Revolution meant that they got the big cities quicker and fed them with bland canned goods before they worked out the fresh goods logistics.
Cheese eating surrender monkeys. Created a state of the art defence system but didn't extend it across the gap where 'the Germans will never invade through such rough terrain' although they did before during WWI.
Not just during but long after (well into the 1950s). People generally don't understand that Britain literally bankrupted herself holding out against Germany, then got to watch as the former Axis powers rebounded faster than they did.
Less we bankrupted ourselves and more the Americans bankrupted us. America put a lot of effort in the early 20th century to undermining the influence of the BE and was far more concerned with building up west Germany as a barrier to the Soviets than they did with building back up allies like the UK and France.